Add BSD-2-Clause license headers to the o2 files

As stated in the license file, o2 is BSD-2-Clause.

Ironically, the only files with a license header were BSD-3-Clause.

resources/tomboynotes/o2/LICENSE

-Copyright (c) 2012, Akos Polster
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without 
-modification, are permitted provided that the following conditions are met:
-
- * Redistributions of source code must retain the above copyright notice, this
-list of conditions and the following disclaimer.
-
- * Redistributions in binary form must reproduce the above copyright notice, 
-this list of conditions and the following disclaimer in the documentation 
-and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
-OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

resources/tomboynotes/o2/o0abstractstore.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O0ABSTRACTSTORE_H
 #define O0ABSTRACTSTORE_H
 

resources/tomboynotes/o2/o0baseauth.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QDataStream>
 #include "debug.h"
 

resources/tomboynotes/o2/o0baseauth.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O0BASEAUTH_H
 #define O0BASEAUTH_H
 

resources/tomboynotes/o2/o0globals.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O0GLOBALS_H
 #define O0GLOBALS_H
 

resources/tomboynotes/o2/o0requestparameter.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O0REQUESTPARAMETER_H
 #define O0REQUESTPARAMETER_H
 

resources/tomboynotes/o2/o0settingsstore.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QCryptographicHash>
 
 #include "o2/o0settingsstore.h"

resources/tomboynotes/o2/o0settingsstore.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O0SETTINGSSTORE_H
 #define O0SETTINGSSTORE_H
 

resources/tomboynotes/o2/o0simplecrypt.h

 /*
-SPDX-FileCopyrightText: 2011 Andre Somers 
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above copyright
-      notice, this list of conditions and the following disclaimer in the
-      documentation and/or other materials provided with the distribution.
-    * Neither the name of the Rathenau Instituut, Andre Somers nor the
-      names of its contributors may be used to endorse or promote products
-      derived from this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL ANDRE SOMERS BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+    SPDX-FileCopyrightText: 2011 Andre Somers 
+
+    SPDX-License-Identifier: BSD-3-Clause
 */
 
 #ifndef SIMPLECRYPT_H

resources/tomboynotes/o2/o1.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QCryptographicHash>
 #include <QNetworkRequest>
 #include <QNetworkAccessManager>

resources/tomboynotes/o2/o1.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O1_H
 #define O1_H
 

resources/tomboynotes/o2/o1requestor.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QDateTime>
 #include <QNetworkReply>
 #include <QNetworkAccessManager>

resources/tomboynotes/o2/o1requestor.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O1REQUESTOR_H
 #define O1REQUESTOR_H
 

resources/tomboynotes/o2/o1timedreply.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QTimer>
 #include <QNetworkReply>
 

resources/tomboynotes/o2/o1timedreply.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O1TIMEDREPLY_H
 #define O1TIMEDREPLY_H
 

resources/tomboynotes/o2/o2.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QList>
 #include <QPair>
 #include <QMap>

resources/tomboynotes/o2/o2.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O2_H
 #define O2_H
 

resources/tomboynotes/o2/o2reply.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QTimer>
 #include <QNetworkReply>
 

resources/tomboynotes/o2/o2reply.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O2TIMEDREPLYLIST_H
 #define O2TIMEDREPLYLIST_H
 

resources/tomboynotes/o2/o2replyserver.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include <QTcpServer>
 #include <QTcpSocket>
 #include <QByteArray>

resources/tomboynotes/o2/o2replyserver.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O2REPLYSERVER_H
 #define O2REPLYSERVER_H
 

resources/tomboynotes/o2/o2requestor.cpp

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #include "debug.h"
 #include <QTimer>
 #if QT_VERSION >= 0x050000

resources/tomboynotes/o2/o2requestor.h

+/*
+    SPDX-License-Identifier: BSD-2-Clause
+*/
+
 #ifndef O2REQUESTOR_H
 #define O2REQUESTOR_H